Kaoru Tsubaki

Known by some students by the nickname "Ol' Sideburns," this cram school instructor serves as the dedicated Physical Education teacher. He is most famous for his unpredictable behavior, frequently abandoning his lessons or canceling classes without warning. These sudden departures are always triggered by mysterious phone calls from a woman he affectionately refers to as "Kitten," leaving his pupils to wonder about the true nature of their teacher's secret personal life.